I notice that there has been no response to your post. So I try to say something.
Most round eggplants that I have seen in Asian market are small, maybe the size of a large egg (Eppplant!!).
One variety is Indian which is dark purple( I have bought and cooked some. They are very tasty and had hard feel to them). Another is Thai eggplant which is mostly green , speckled with white.
I remember seeing white ones too which were oval, slightly longer than an egg and probably about the same diameter as an extra large egg.
I would think that white eggplants should be white when matured and may have green stripes or spot when not quite ripe.
My suggestion to you is to pick one, cut it and check the seeds. If seeds are pronounced then the eggplant is ripe but if the seeds are stil soft and not quite formed then it is too young.

Thanks for the comment Cyrus. I have the Thai white eggplant, brought the seed packet back from my last trip to Thailand. I helped out with the cooking on occasion while there but missed out seeing the eggplant before it was cooked. I did cut into one today, the consistancy of an apple but the seeds are brown and well formed. I'll try cooking some next week.... or sooner.

Hi thaigrower,

If your eggplant seeds are brown and well formed then your eggplant might be past its prime. Try to pick the eggplant when seeds are still white and almost blend in with the flesh. I think you might find that the eggplant with well formed seeds will be a tad bitter. I grow different types and always pick young when the seeds are still immature. If the taste you prefer is a bit stronger then using more mature fruit is surely OK.

DL

As "dancinglemons" said, you should harvest your eggplants sooner. Probably the reason for waiting too long is that you expect them to grow bigger. But those varieties won't get very big. So as soon as they get to normal size, pick them. Eggplants are not supposed to ripen like tomatoes but they are like zuchinnies, cucumbers. But the differenc is that eggplants grow very slowly as compared to zuchinnies and they will not overgrow in size either.
cyrus

Harvest your eggplant when itÂs reached the right size for its variety and when its colorÂwhether white, purple or another shadeÂis uniform, says Michael Colt, University of Idaho extension horticulturist. "If you press the side of a fruit slightly and an indentation remains, the fruit is mature," he says. "Harvest before the flesh becomes tough."

Eggplant can be harvested nearly anytime. It's hardly ever too young - except when just out of the flower. But it can be over-ripe - usually turning to yellow - or like the above said - the seeds are turning brown. These little eggplants are great in Asian dishes from Thai curries to Indian dishes. They hold up to cooking a bit better than others, staying firmer. They also pickle really well. Some of these are even used raw in some SE Asian dishes - where their crispy texture is favored.

My DW indian friend said I picked my egg plant too early, so she let it ripen a week or too.

I do not eat EP, but grow it for my wife & friends.